Image processing apparatus, imaging apparatus, image processing method, and storage medium for performing a restoration process for an image

An image processing apparatus includes a memory configured to store a plurality of image restoration filters depending on an F-number, and at least one processor coupled to the memory, and serving as an acquirer configured to acquire a plurality of first image restoration filters according to an imaging condition from among the plurality of image restoration filters, and an image restorer configured to perform a restoration process for an image through a predetermined calculation process based on the plurality of first image restoration filters. The image is obtained via an imaging optical system that includes an optical element having a transmittance distribution where a transmittance continuously changes in at least a partial area.